Author: fperrad
Date: Sun Jan 15 22:50:57 2006
New Revision: 11205
Modified:
trunk/languages/lua/classes/luanil.pmc
Log:
Lua :
This patch changes LuaNil PMC, it used to be a singleton, this patch makes it a
normal PMC.
some other methods are implemented for morphing into other Lua types
(LuaString, LuaNumber, LuaBoolean).
Courtesy of Klaas-Jan Stol.
+ change Parrot_PMC_typenum by pmc_type
Modified: trunk/languages/lua/classes/luanil.pmc
==============================================================================
--- trunk/languages/lua/classes/luanil.pmc (original)
+++ trunk/languages/lua/classes/luanil.pmc Sun Jan 15 22:50:57 2006
@@ -8,8 +8,13 @@ classes/luanil.pmc - Lua Nil
=head1 DESCRIPTION
-C<LuaNil> extends C<Python None> to provide a class with the behaviour of
-the Lua C<Nil> value.
+C<LuaNil> provides a class with the behaviour of the Lua C<Nil> value.
+Implementation is based on the Undef PMC. LuaNil is no longer a singleton;
+this would be a problem, as all uninitialized values in Lua are LuaNil.
+If some value is assigned, the LuaNil should morph into the correct type,
+and so a new PMC is constructed anyway. Therefore, we may as well create
+a new PMC right away. Also, creating a new PMC from a singleton class is
+troublesome (if not possible?).
=head2 Overloaded Methods
@@ -22,20 +27,27 @@ the Lua C<Nil> value.
#include "parrot/parrot.h"
static STRING *string_representation;
-static PMC *Lua_Nil;
+static INTVAL dynclass_LuaNumber;
+static INTVAL dynclass_LuaString;
+static INTVAL dynclass_LuaBoolean;
-pmclass LuaNil
- singleton
- extends None
+pmclass LuaNil
dynpmc
group lua_group
hll Lua {
-/* Class initialization. Caches constant strings that will be used later.
+/*
+* Class initialization. Caches constant strings that will be used later.
*/
void class_init() {
if (pass) {
string_representation = const_string(INTERP, "nil");
+ dynclass_LuaNumber = pmc_type(INTERP,
+ string_from_const_cstring(INTERP, "LuaNumber", 0));
+ dynclass_LuaString = pmc_type(INTERP,
+ string_from_const_cstring(INTERP, "LuaString", 0));
+ dynclass_LuaBoolean = pmc_type(INTERP,
+ string_from_const_cstring(INTERP, "LuaBoolean", 0));
}
}
@@ -78,24 +90,11 @@ Return the string "nil".
return string_representation;
}
-/*
-
-=item C<void* get_pointer()>
-
-=item C<void set_pointer(void *ptr)>
-
-These two functions are part of the singleton creation interface. For more
-information see F<src/pmc.c>.
-
-=cut
-
-*/
- void* get_pointer() {
- return Lua_Nil;
- }
- void set_pointer(void* ptr) {
- Lua_Nil = (PMC*)ptr;
+ PMC* clone () {
+ PMC* dest = pmc_new(INTERP, SELF->vtable->base_type);
+ memcpy(&PMC_union(dest), &PMC_union(SELF), sizeof(UnionVal));
+ return dest;
}
/*
@@ -109,23 +108,60 @@ Return always true.
*/
PMC* logical_not (PMC* dest) {
if (!dest)
- dest = pmc_new(INTERP, pmc_type(INTERP,
- string_from_const_cstring(INTERP, "LuaBoolean", 0)));
+ dest = pmc_new(INTERP, dynclass_LuaBoolean);
VTABLE_set_integer_native(INTERP, dest, 1);
return dest;
}
-}
+/*
+
+=item C<INTVAL defined()>
+
+"nil" in Lua is always undefined.
+
+=cut
+
+*/
+ INTVAL defined() {
+ return 0;
+ }
/*
-=back
+=item C<void set_number_native(FLOATVAL)>
+
+=item C<void set_string_native(STRING *)>
-=head1 AUTHORS
+=item C<void set_bool(INTVAL)>
-Original code by Klaas-Jan Stol.
+Methods to set a new value to this LuaNil PMC. First,
+this PMC is morph'ed into the correct Lua type.
+
+=item C<void morph(INTVAL)>
+
+Morph to another Lua type.
=cut
*/
+ void set_number_native(FLOATVAL value) {
+ VTABLE_morph(INTERP, SELF, dynclass_LuaNumber);
+ VTABLE_set_number_native(INTERP, SELF, value);
+ }
+
+ void set_string_native(STRING *value) {
+ VTABLE_morph(INTERP, SELF, dynclass_LuaString);
+ VTABLE_set_string_native(INTERP, SELF, value);
+ }
+
+ void set_bool (INTVAL value) {
+ VTABLE_morph(INTERP, SELF, dynclass_LuaBoolean);
+ VTABLE_set_bool(INTERP, SELF, value);
+ }
+
+ void morph(INTVAL new_type) {
+ pmc_reuse(INTERP, SELF, new_type, 0);
+ }
+
+}
